The present invention relates to an input device, and particularly to an input device that senses hand movement. The hand-movement-sensing input device enables command and cursor movement signals to be sent to a computer without the need for physical manipulation of a material object such as a mouse, touchpad, tablet, or keyboard.
In order to operate a conventional computer system, it is necessary to provide some sort of device, such as a computer mouse, keyboard, tablet, touch pad, or the like, that can be physically manipulated by a user in order to enable the user to communicate with the computer. In general, such user-handled input devices occupy a large space on a working platform. In the case of a keyboard, the occupied space is entirely wasted if there is no need to input large amount of text. While a computer mouse requires less space, it hampers the free movement of a user""s hand, and also tends to cause injury to the hand.
In order to overcome the drawbacks mentioned above, WO00/21024 and WO 02/50762 disclose a virtual input device, in which an image of a keyboard or a mouse is projected onto a working platform. By detecting light reflected from the user""s hand, a corresponding operation or cursor movement on a display will be simultaneously initiated or controlled. To implement the virtual input, a precise detecting and receiving sensor needs to be carefully installed to enable the computer system to retrieve a corresponding input signal or command from the light reflected by the user""s hand. Therefore, the cost to achieve practical use of the virtual input is inevitably high. Furthermore, the precise working of the detecting or receiving sensor is adversely affected by ambient illuminating light.
It is therefore a primary objective of the present invention is to provide an input device that does not require physical manipulation by a user, in contrast to known input devices such as computer mice and keyboards, and yet that is low in cost and relatively insensitive to ambient illuminating light.
In accordance with the principles of a preferred embodiment of the invention, this objective is achieved by connecting a plane-position detector and an altitude-position detector to a computer, the intersection of the areas sensed by the detectors defining a three-dimensional sensing area. The detectors may be, by way of example and not limitation, CCDs, CMOS detectors, or infrared or ultrasound sensors. When a user places his hand within the sensing area, the plane-position detector detects the horizontal movement of the hand so as to correspondingly create a cursor-moving signal, while the altitude-position detector detects the upward and downward movement of the hand to generate a command signal that, for example, may be used to simulate the xe2x80x9cbutton-clickxe2x80x9d of a conventional mouse.
When the detectors are CCDs or similar image capture devices, the apparatus of the invention may be used to in the following manner: An image of the user""s hand is captured by the plane-position detector and then processed to retrieve an image feature in the form of a triangle composed of two lateral sides of the hand and a finger, from which horizontal movement of the user""s hand may be deduced and a cursor-moving signal generated. Vertical movement of a portion of the hand, preferably the user""s finger, is detected by processing of an image captured by the vertical position sensor in order to identify the portion of the user""s hand, and by then detecting up and down movement of the portion of the user""s hand in order to generate command signals.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings.